The present invention relates to a lapping machine, more precisely relates to a lapping machine in which a work piece is lapped, in a plurality of lapping steps, with a plurality of kinds of abrasive grains.
In manufacturing steps of an MR head of a magnetic disk drive unit, a work piece is lapped so as to have a prescribed electric resistance. Conventionally, the work piece is lapped with one kind of abrasive grains. These days, compact and high density MR heads are required, and high lapping accuracy, e.g., 20-30 nm, is required. Thus, a plurality of lapping steps, i.e., a first (rough) lapping step to a.final (finish) lapping step, are executed.
In the manufacturing steps of the MR head, the work piece is lapped in three lapping steps: the first lapping step, an intermediate lapping steps and the final lapping step. A problem of the lapping steps is abrasive grains left on a lapping plate. A grain size of the abrasive grains in each lapping step is different. Namely, the grain size is changed from large grains to fine grains in order. If the abrasive grains of a former lapping step are left on the lapping plate, the work piece will be scratched or damaged in the next lapping step. As described above, the high lapping accuracy is required, so the problem of the abrasive grains left on the lapping plate cannot be ignored. Therefore, the abrasive grains of the former lapping step must be completely removed from the lapping plate.
Conventionally, the abrasive grains are washed off, from the lapping plate, with a large amount of water. The abrasive grains left on the lapping plate can be washed off, but it takes a long time to completely wash the lapping plate. Working efficiency is important for manufacturing the MR heads. The working efficiency of the conventional lapping machine cannot be higher. Further, it is difficult to perfectly remove the abrasive grains by water.
Note that, in some cases, a correction ring is attached to a lapping face of the lapping plate. The correction ring makes the lapping face flat. The correction ring removes the abrasive grains but cannot remove them completely.
An object of the present invention is to provide a lapping machine in which abrasive grains can be efficiently and perfectly removed from a lapping plate.
To achieve the object, the lapping machine of the present invention comprises: a lapping plate having a lapping face, the lapping plate rotating about a rotary shaft; a moving member having a wiping face extended in a longitudinal direction, the moving member moving, in a plane parallel to the lapping face of the lapping plate, in the direction perpendicular to the wiping face; and a driving mechanism for moving the moving member.
In the lapping machine of the present invention, the moving member securely catches and removes foreign substances, including abrasive grains, left on the lapping plate. In comparison with the manner of washing the lapping face with water, the foreign substances, including the abrasive grains, left can be perfectly removed in a short time and the working efficiency of the lapping steps can be highly improved. By improving the working efficiency, manufacturing cost can be reduced.
In the lapping machine, the moving member may be connected to a supporting shaft and capable of turning about the supporting shaft. With this structure, the moving member is capable of moving on the lapping plate with a circular track.
In the lapping machine, the supporting shaft may be located outside of an outer edge of the lapping plate. With this structure, the whole lapping face can be wiped and the foreign substances including the abrasive grains can be perfectly removed therefrom.
The lapping machine may further comprise a control mechanism for adjusting a pressing force which presses the moving member onto the lapping plate. With this structure, foreign substances including the abrasive grains can be securely removed.
The lapping machine may further comprise an adjusting mechanism for adjusting an angle between the moving member and the lapping face of the lapping plate. With this structure, foreign substances including the abrasive grains can be securely removed.